Flameproof cable



Jan. 31, 1933. w. c. ROBINSON 1,395,893

' FLAMEPROOF GABLQ Filed July 5, 1929 Qvwantoc hizaw a t tom 411441Patented Jan. 31, 1933 UNITED STATES PATENT OFFICE mm C. ROBINSON, OISEWICKLEY, PENNSYLVANIA, ASSIGNOB '10 NATIONAL mmrc PRODUCTSCORPORATION, 01' NEW YORK, N. Y., A CORPORATION OI DELAWARE FLAHEPROOICABLE Application fled m s, ma. Serial no. man.

This invention relates to improvements in flame roof or slow burninginsulated wires or cab es.

According to present practice such wires l are made by employing stearinpitch as a flame retardent and y utilizing a waxy material such asparaflin for the outer surface which provides a slick and non-stickyfinish. With certain kinds of wire it is desirable that the color orcoat characteristic of the w re be secured from the coloring of thebraiding. When white braiding is employed the useof stearin pitch is notwholly satisfactory.

It is accordingly, one object of the present 16 invention to provide aninsulated wire with a novel flame retardent of such character that suchflame retardent is adaptable for use with light and even white coloredbraiding.

The invention is not, however, limited to 80 flame retardent for wireswith white braiding since the novel flame retardant can also be usedwith colored braiding and particularly with such braiding which is oflig t or bright color.

It is a further object of the resent invention to provide an improvedinsulated w re or cable which has flame proof characteristics and inwhich the distinguishing or code coloring of the cable may be securedfrom the coloring or color characteristics of the braid itself and whichcable also has a slick exterior so as to facilitate the drawing of thewire and to prevent the convolutions of the cable sticking to each otheror presenting a sticky or tacky surface to the hands of the user.

It is a further object of the present invention to provide an improvedinsulated wire or cable in which the flame retardant material is kept inplace upon the braiding by the outer slick finishing material.

Other objects and advantages will be hereinafter set forth in theaccompanying specitication and claims and shown in the drawing which byway of illustration shows a prcferred embodiment of the invention.

In the drawing:

The fi re is an illustration of a wire incorporating the presentimprovements.

Referring to the drawing 10 is the copper conductor 11 is the usualrubber insulated covering, 12 is a braid, this may be of white braidedyarn fabric or if desired it may be a braid in which the yarn is coloredbut in distinguishing color.

After the braid is applied in the usual way the braiding is saturatedwith a solution of water glass or silicate of soda. This is designated13. The water glass thoroughly impregnates the braid and makes the sameflame proof. The use of water glass also affords the desired flameretardent and resisting characteristic to the complete cable. After thewater glass is applied to the braid, the cable is thoroughly dried sothat all moisture is removed and so that the water glass is changed intoa dry condition.

The final step in the preparation of the wire resides in the applicatlonof a thin coating of paraflin or wax-like material 14 over the braidwhich as before stated, is saturated and impregnated with the waterglass material. This wax-like material provides a smooth slick andnon-sticky finish to the cable so that it can be readily drawn wheninstalled. The wax-like material also provides a non-sticky outersurface for the cable.

The waxy material also co-acts with the water glass or silicate of sodamaterial to hold it in place and to prevent its being shaken off fromthe cable when the latter is shipped or when it is in use.

In the drawing the water glass material which is designated 13 and thethin waxy Y outer coating designated 14 are shown somewhat exaggcratedin thickness for the sake of clarity of illustration. In practice thewater glass which is the fire retardent material would thoroughlypermeate in the braiding and its presence would only slightly if at allincrease the diameter of the braided wire. The paraflin or wax-likeouter coating is also somewhat exaggerated in thickness for the samereason. In actual practice this coating is quite thin and its use doesnot materially increase the thickness of the silicate of sodaimpregnated braided cable.

Cables made according to the above invention present a brilliance ofcolor heretofore not readily obtainable when other flame retan-dentmaterials are employed. Such cable also has excellent flame retardentcharacteristics and it has in addition the desirable exterior slick andnon-sticky finish.

What I claim is:

p 5 1. An insulated wire including a conductor exteriorly insulated withrubber and the rubber being covered over with a light colored braid,said braid being exteriorly covered with silicate of soda for fireproofing purposes and to provide a fire proofing material which istransparent so that the-color of the braid can be seen through thetransparent silicate of soda material. and a thin coating of transparentwax applied directly over the silicate of soda coating to maintain thiscoating in'place and to provide a transparent slick outer finish whichis of transparent nature so that the color of the braid is visibletherethrough.

2. A cable comprising the usual conductor, a rubber insulating coveringtherefor, a braided cover for the insulation, which braiding is of lightcolor and outer coatings for the braiding both of which are transparentso that the light color of the braid may be viewed through said coating,one coating being disposed directly-upon the braid and com prisingtransparent silicate of soda, and the other coating which is upontheou'termost portion of the cable comprising a thin layer oftransparent wax. I I

3. A cable having a light colored braided covering impregnated withsilicate of soda to provide fire retarding characteristics thereto andto provide a transparent coating through which the light color of thebraid may be visible, said cable also having as the outermost coatingofthe cable an outer surface of transparent wax-like material through 40which the light color of the braid is Visible.

In testimony whereof I hereto afiix my signature.

WILLIAM C. ROBINSON.

